Precession system for directional gyroscopes



Dec. 20, 1949 P. A. NoxoN 2,492,057

PRECESSION SYSTEM FOR DIRECTIONAL GYROSCOPES Filed Feb. 16, 1948 INVENTOR.

Patented Dec. 20, `1949 PRECESSION SYSTEM FOR DIRECTIONAL GYROSCOPES Paul A. Noxon, Tenafly, N. J assigner to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application February 16, 1948, Serial No. 8.57.6

2 Claims. (Cl. i4- 5.43)

This invention relates to gyroscopic instruments and more particularly to improved torque exerting means applicable for use as a precession effecting means for controlling directional gyroscopes. l

Directional gyroscopes are usually given three' degrees of freedom so that they are uninfluenced by gravity or other acceleration forces. Such gyroscopes are usually mounted with a substantially horizontal spin axis, oscillatory about a second horizontal axis at right angles to the spin axis, and for turning about a vertical axis. The spin axis of a directional gyroscope has a tendency to become inclined to the horizontal in a relatively short time thereby diminishing the directive force of the gyroscope. To correct the departure of the gyroscope spin axis from its reference axis, an air jet from the rotor casing is directed against a wedge shaped member or blade mounted on the normally vertical ring. The reaction to the air jet causes a torque to be exerted which causes a precession of the gyroscope to correct the spin axis.

The present invention provides means for raising the efficiency of the air jet to increase the torque applied to the vertical axis of the ring whereby the spin axis of the gyroscope is returned more rapidly to the reference axis.

An object of this invention is to provide means for increasing the sensitivity of a directional gyroscope.

Another object of this invention is to provide improved torque exerting means to level the rotor case of a gyro instrument.

The foregoing and other objects and advantages oi the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only, and are not to be construed as dening the limits of the invention.

In the drawings, wherein like reference numerals refer to like parts,

Figure 1 is a side elevation of a directional gyroscope in which my improved torque producing means has been incorporated.

Figure 2 is a sectional view taken on line 2--2 when the rotor casing is tilted about its horizontal axis.

The instrument in which this invention is illus tratively embodied as shown in Figure 1 is an electrically spun directional gyroscope of the type CilA which may or may not be slaved to or controlled from a remote-magnetic compass. The illustrated instrument includes a sealed outer casing 5 llaving a shock-proof mounting E in which a conventional gimbal ring 1 is mounted for movement about a vertical axis formed by the respective upper and lower trunnions 8 and 9 journalled in suitable bearings (not shown) in the mounting Ii. Gimbal ring 'I also supports the rotor bearing case Ill of the gyro instrument with freedom of movement about a horizontal axis provided by trunnions I I and I2 extending from rotor bearing case I0 and suitable bearings (not shown) in the opposite legs of the said vertical ring. The gyro rotor (not shown) is suitably journalled within rotor bearing case III, the spin axis of the gylo rotor being normally disposed at right angles to both the vertical axis of gimbal ring 1 and the horizontal axis of the rotor bearing case I0. The gyro rotor is spun by means of a polyphase motor (not shown) which is energized from a suitable source of electrical energy.

The rotor bearing case II) is shown as pneumatically leveled by means of an air jet which issues from the tangentially directed nozzle I3 mounted on rotor bearing case. The bearing case I0 is provided with a plurality of openings I4 which in conjunction with gyro rotor provided with a plurality of slots (not shown) acts as a turbine pump to drive air through nozzle I3. The air jet is directed against a knife edge I5 mounted on the gimbal ring 1, the knife edge I5 normally bisecting the air jet from nozzle I3 when the rotor vbearing case I0 is in a leveled position so that no disturbing torque is developed. In the event of inclination of rotor bearing case I0 about the axis II-I2, the air jet strikes only one side of the knife edge I5 whereupon a torque is developed about the vertical axis 8 9 of gimbal ring I to displace the gimbal ring in response to which the rotor bearing case I0 is precessed to its normal leveled position.

Previously, if the rotor bearing case III was tilted to such a degree that the air jet did not impinge on knife edge I5 but against the under side of gimbal ring 'I, the air jet there functioned independently of knife edge I5 to exert a leveling torque about the vertical axis of gimbal ring 1. The horizontal component of the direct reaction of the air jet, which was present to some extent for small tilts, was effective to erect the gyroscope slowly without the aid of knife-edge I5.

By aixing to the gimbal ring 'l a plurality of vanes I 6 (Fig. 2) I increase the speed at which the case I0 is returned to its level position. The

vanes I6 are disposed on both sides of the knife edge l5 and bear an angular relation with respect to the air jet from nozzle I3 that the vane surfaces are tangentially impinged. An increase in the horizontal component of the reaction to the air jet is thereby produced, increasing the torque applied to gimbal ring 'l about the vertical axis 8 9. The increased torque brings rotor bearing case I0 back to its leveled position more rapidly to prevent thereby the diminishing of the directive force of the directional gyroscopeT As will now be apparent to those skilled in the art, a novel and desirable improvement has been provided for the restoration and maintenance of the spin axis of a directional gyroscope in a leveled position so that its directive force may not be diminished.

Although but one embodiment of the invention has been illustrated and described in detail, vari,- ous changes and modifications in the form and relative arrangement ef` tile perte which, will new appear te. those sk," le@ te the, mer be merle Witheet departing: ,freni the, Scene Qf the, inveilf. tion.

. I claim:

1,. In a directional gyroeeope having a erro rotor `Casing mounted for oscillation about a lgiorizontal axis in a vertical gimbal ring rotatable about a Vertical axis and precessional means in, cluding a sharp-edged deiiectinemeans mounted 0n said vertical ring and a nozzle on the rotor casing for producing an airv jet which reacts with said sharp edged deflectng means t0 exert a lll,

torque upon said vertical ring, the combination with said precessional means of means secured to said vertical gimbal ring and adapted to react with said air jet to increase the torque exerted upon the vertical gimbal ring about its vertical axis.

2. In a directional gyroscope having a gyro rotor casing mounted for oscillation about a horizontal axis in a vertical gimbal ring rotatable about a vertical axis and precessional means including a sharp-edged deecting means mounted on said vertical ring and a nozzle on the rotor casing for producing an air jet which reacts with said sharp edged deflecting means to exert a torque upon said vertical ring, the combination with said precessional means of a plurality of Yanes secured to said vertical gimbal ring on both sides vof said deflecting means and adapted to react with said air jet to increase the torque exerted upon the vertical gimbal ring about its Vertical axis.y

permettere circa The following references are of record in the le of this patent:

UMTED SATLTES PATENTS Number Name Date 1,197,134 Leavitt. T sept. 5, 191e 2,174.77? Carter et al. eet., 3., 1939. 2,248,141 Von Manteuiel July 8, 194i 

